Progress toward the Enantioselective Synthesis of Curcusones A–D via a Divinylcyclopropane Rearrangement Strategy
摘要:
We report our iterative efforts toward the divergent total syntheses of curcusones A-D via Suzuki coupling, intramolecular cyclopropanation, and a key divinylcyclopropane rearrangement. Progress of our synthesis was repeatedly challenged by the highly substrate-dependent cyclopropanation step, which we could ultimately overcome by judicious choice of substituents on the six-membered ring fragment.
[EN] 4-SUBSTITUTED IMIDAZOLE-2-THIONES AND IMIDAZOL-2-ONES AS AGONISTS OF THE ALPHA-2B AND ALPHA-2C ADRENERGIC RECEPTORS [FR] IMIDAZOLE-2-ONES ET IMIDAZOLE-2-THIONES 4 SUBSTITUES COMME AGONISTES DES ADRENO-RECEPTEURS ALPHA-2B ET ALPHA-2C
The Palladium-Catalyzed Aerobic Kinetic Resolution of Secondary Alcohols: Reaction Development, Scope, and Applications
作者:Davidâ C. Ebner、Jeffreyâ T. Bagdanoff、Ericâ M. Ferreira、Ryanâ M. McFadden、Danielâ D. Caspi、Raissaâ M. Trend、Brianâ M. Stoltz
DOI:10.1002/chem.200902172
日期:2009.12.7
and tert‐butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23 °C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kineticresolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good‐to‐excellent
已经开发出第一个钯催化的仲醇对映选择性氧化反应,利用容易获得的二胺(-)-金雀花石作为手性配体,分子氧作为化学计量氧化剂。关于碱基和氢键供体作用的机制见解导致了对原始系统的一些改进。也就是说,碳酸铯和叔丁醇的添加大大提高了反应速率,促进了快速分辨率。使用氯仿作为溶剂允许在 23 °C 下使用环境空气作为终端氧化剂,从而提高催化剂选择性。这些改进的反应条件使得能够以良好至优异的选择性因子成功地将苄基、烯丙基和环丙基仲醇动力学拆分为高对映体过量。该催化剂体系也已应用于内消旋二醇的去对称化,提供高产率的对映体富集的羟基酮。
Anti-ischemic compounds
申请人:Societe de Conseils de Recherches et d'Applications Scientifiques (S.C.R.A.S.)
公开号:US06780887B1
公开(公告)日:2004-08-24
The present invention is related to a compound of formula (I), salts and pro-drugs of the compound (I) and methods for treating and/or preventing partial or total ischemia, methods for treating and/or preventing pathologies associated with ischemia or with mitochondrial deficiencies.
Enantioselective total synthesis of ginkgolide derivatives lacking the tert-butyl group, an essential structural subunit for antagonism of platelet activating factor
作者:E.J. Corey、K.Srinivas Rao
DOI:10.1016/s0040-4039(00)92265-2
日期:1991.1
An enantioselective total synthesis of the ginkgolide B analog 3 is reported along with the results of bioassays for antagonism of platelet activating factor. The three orders of magnitude difference in bioactivity of 2 and 3 demonstrates that the tert-butyl group of the ginkgolides is essential for anti-PAF potency.
[EN] 4-SUBSTITUTED IMIDAZOLE-2-THIONES AND IMIDAZOL-2-ONES AS AGONISTS OF THE ALPHA-2B AND ALPHA-2C ADRENERGIC RECEPTORS<br/>[FR] IMIDAZOLE-2-ONES ET IMIDAZOLE-2-THIONES 4 SUBSTITUES COMME AGONISTES DES ADRENO-RECEPTEURS ALPHA-2B ET ALPHA-2C
申请人:ALLERGAN INC
公开号:WO2003099795A1
公开(公告)日:2003-12-04
Compounds of Formula (I): where X is S and the variables have the meaning defined in the specification are specific or selective to alpha2B and/or alpha2C adrenergic receptors in preference over alpha2A adrenergic receptors, and as such have no or only minimal cardivascular and/or sedatory activity. These compounds of Formula (I) are useful as medicaments in mammals, including humans, for treatment of diseases and or alleviations of conditions which are responsive to treatment by agonists of alpha2B adrenergic receptors. Compounds of Formula (I) where X is O also have the advantageous property that they have no or only minimal cardivascular and/or sedatory activity and are useful for treating pain and other conditions with no or only minimal cardivascular and/or sedatory activity.